Apparatus for localizing mine explosions by rock-dust barriers.



1. s. GRASTY & w. s. RODMAN. APPARATUS FOR LOCALIZING MINE EXPLOSIONS BY ROCK DUST BARRIERS.

APLICATION FILED @C1-'.27' |915- 1,261,922. Patented Apr. 9, 1918-.

vnniagin'n srnrns narnnr ernten .Ionn sHARsHnLL ennsrx Ann WALTEn srInLnoN noni/IAN, or UNIVERSITY,

. f VIRGINIA.

nrPAnn'rUs non LocnLIz-ING MINE nx-ILosrons BY'nocx-nus'r Banninns.

To all whom t may concern.'

Be it known that we, Jenn SHAnsHALL GRASTY, a citizen of the United-States, and residing at University, intthe county of Albemarle and State of Virginia, and l/VALTER Snn'LnoN RODMAN, a citizen of the United States, and resident of the saine place, have invented certain new and use ful Improvements in Apparatus for Localizing yMine Explosions by Rock-Dust Barriers, of which the following is a specification. f

`The Taffanel method of controlling and preventing the propagation of minefexplosions consists in launching a mass of rock dust kor other finely `ground non-inflammable dust into the yair blast that always precedes a dust-explosion, and t0 which the possibility of a ydust explosion is` due.

The air blast, termed by the English the pioneering'wave;7 by its eddying currents mixes the non-inflammable dustV with the coal dust, so when the flameof the explosion reaches the dense cloud ofdust, in which inert dust greatly predominates, ,the `latter extinguishes the. flame by absorbing heat; also, on account of the large amount used, doubt-l lessr each particle of coal'dust is surrounded by many particles of inert dust, which thus form a screen betweenv the flame andthe coal dust. The flame of the explosion is sometimes ,immediately extinguished, but a dis-k tance of 50. feet or thereabout maybe traversed before the inert dust rborne by the explosion wave extinguishes all the flame.

It has been proposed to place the inert dust `on shelves, by which it will be picked'up by the ioneelill Wavelor 'to MC@ Che dust in suitable containers provided with means,

actuated by tripping vanes in advance of the containers, for dumping their contents, into the-,passage to be protected. Inasmuch, as velocities of the propagation of the explosion'are sometimes as low asv 100 feet per second, with corres ondingly low pressure gradients in frontr of the explosion, the'tripping vanes, which are actuated by the pressures due to air velocities, are not satisfactory or certain in their action. On the other hand,'the veloci ty of propagation of the explosion is sometimes as great yor greater than 3000 feet per second, so thatY any system whch'rslesfoll the ,Pioneering `Speccatin of Letters Patent.

Patented Apr. 9, 1918.

Application filed October 27, 1915*. Serial No. 58,2913.`

wave to create the dust barrier may at times be too sluggish in its action, and c'reatesuch a rbarrier not in advance of the explosion, but in the rear 0f a part thereof.

We propose to overcome these difficulties (a) Initiating the release of the inert rock dust or other substance by a device located in advance of the barrier and dependent for its action upon the rise of tempera-y ture attendant upon the explosion, and thus independent of the rate of Ypropagation thereof, in that the thermostatic device will be sulliciently sensitive to respond t0 the heat attendant upon any gas or dust explo'- sion occurring in itsvicinity, whereby ythe dust will be projected into the passage in advance of'its pioneering wave. l

(b). prolonging the duration of the time during which the dust is launched, so that while the initiation of the dust barrier may precede the passage of the pioneering wave, additional dust will be fed during, and if desired, after the passage of such wave.

It will be noted that while these two features of our invention are capa-ble of conjoint use, they are each capable of use with- Y out the other. f l

We further propose to project andsus forcibly blowing the dust into passage by air pressure other than that due to the explosion, the result of which is to create a dust barrier by iilling the passage to be protected by the non-inflammable and non-ex plosiveV mixture formed by the gases and dust injected into such passage, or by the action of the dust of such mixture on the inflammable material previously in such pas- Sge- Ouri-nvention, therefore, relates to the means for initiating the release of the inert dust, and means of projecting a dust barrier, and in the combination of such means,`and in the arrangement and construction of the parts of which it is composed, as will be hereinafter mbre fully described and claimed. j

Referring to the accompanying drawings, in which .corresponding parts are desig- Wide bottom. The box is Vprovided With drop bottom Kd, controlled by a latch, Which When released by the solenoid G in the thermostatic circuit C, will release the bottom. It is unnecessary to describe in detail, the construction of such a barrier as the same is fully described in our other application led of even date herewith, Serial No. 58,292, in which itis speciiically claimed. 'lt will be, noted, however, that upon the breaking of the thermostatic circuit, the bottom Kd Will drop and the contents of the compartment lib will fall into the passage While, due to the restricted bottoms of the compartments K and KC, the contents thereof Will be retarded in their discharge. Y f

We do not in this application make claims to any method herein disclosed, as the same forms the subject-matter of our other application, tiled the 13th day oit May, Serial No. 97,379, as a division hereof in response to demands ot the United States Patent Othce.

Having thus described our invention what We claim and desireto secureby Letters Patcnt is 1. The combination Vwith a suitable lcontainer 'or inert material located adjacent to a mine passage, of an element located in advance of the container, and actuated by the heat of an l explosion occurring adjacent thereto, and means controlled by said element to release the material contained in the container and for launching it into such passage. y

l 2. In a device of ,the character described, the combination with a container for inert dust, of means for blowing the dust intothe passage to be protected, and thereby creating a dust-barrier therein, and means located in advance ot' the desired location or" the dust barrier for controlling the application of the air. j

In a device of the character described, the combination with a. nozzle located adjacent to the passage tobe protected, ot means for feeding inert dust and air under pressure to the said nozzle to create a dust barrier, and means `located in advance of the nozzle for controlling the admission of air to said nozzle. j

4. In a device of the ycharacter decoribed` the combination with a nozzle located adjacent to the passage to be protected, of means for feeding inert dust yand air under pressure to the said nozzle to create a dust barrier, and means located in advance of the nozzle for con trolling the admission of dust to said nozzle. v

5. In a device of the character described, the combination With a nozzle lccatedadj acent to the passage to be protected, of means for feeding inert dust and air under pressure to the said nozzle to create a dust barrier, and means located in advance of the nozzle for controlling the admission oic air and dust to said nozzle.

6. In a device of the character described, the combination with a receptacle for inert dust located adjacent to a passage to be protected, of a source or' air pre. ure, a nozzle connected with a source oi' air pressure and with the receptacle, and means located .in advance of the nozzle and actuated by the heat of an explosive in the vicinity thereof rer controlling the feed of air to the nozzle.

7.v In a device ot' the character described, the combination with a receptacle containing dust under air pressure, and means actuated by an explosion for releasing such dust.

8. In a device oi'f the character described,

the combination with a closed receptacle containing dust under air pressure, and having a valve, of means actuated by an explosion for opening such valve.

9. ln a device of the character described, the combination With a nozzle tor projecting an `inert material, of means actuated by the heat of an explosion for controlling such nozzle.

l0. The combination With a suitable container for inert material located adjacent to ya mine passage, of an element located in advance of the container and actuated by the heat ofV the explosion adjacent thereto, and means controlled by said last-named element to gradually release the material contained in the container, and for slowly launching it into said passage.

. 1l. In a device of the character described, the combination with a container for inert material, of means for continuously projecting inert material in advance of and during the passage opposite such means of the pioneer Wave produced by an explosion, and mea-ns located in advance of the projecting means for controlling the initiation thereof.

In testimony whereof We have hereunto signed our names.

JGHN SHARSHALL GRASTY. VALTER SHELDON RODMAN.

Copies of this patent may be obtained for yfive cents each, by addressing the Commissioner of Fatents,

i Washington, D. C. 

